The present invention relates to lateral insulated-gate bipolar transistors (hereafter, referred to as “IGBT”) and semiconductor integrated circuits for driving a plasma display using such transistors.
Recently, many high blocking voltage power ICs using an SOI substrate have been developed because of their features such that they only need small device isolation areas and are free from parasitic transistors. In developing high blocking voltage power ICs, it will be essential from the viewpoint of the output performances and chip size reduction that high blocking voltage power ICs which directly drive loads should have enhanced performances. However, in the lateral IGBTs, which are mainly employed as output devices in power ICs using an SOI substrate, emitter-gate regions and collector regions are formed on the same surface, which limits a substantial current conduction area to reduce the current capacity per device area.
Furthermore, since the lateral IGBT has a large current component in a direction laterally of the device, it suffers a problem such that the latch-up tends to occur and the range of stable operation of the device is narrow. In consideration of this problem, lateral IGBTs having an increased current capacity per unit area and a wider range of safe operation have been developed, as disclosed, for example, in the specification of Japanese Patent 3,522,983.
According to the features of the lateral IGBT described in the specification of Japanese Patent 3,522,983, in contrast to the usual lateral IGBT in which collector regions and emitter-gate regions are alternately arranged, a plurality of emitter-gate regions are provided between adjacent collector regions. By this structure, it is possible to increase the current capacity without extending the device area and to realize a decrease of the on-voltage.